Decelerometer



Aug. 2o, 1963 E. VAN zYL Em. 3,101,002

DECELEROMETER Filed Nov. 13, 1961 2 sheets-sheet 1 INVENTORS BERNARD VAN Z YL PHIL IP. S TUDER BY @100m2 ATTORNEYS Aug. 20, 1963 B. VAN zYL ETAL DECELEROMETER 2 Sheets-Sheet 2 Filed Nov. 13. 1961 INVENTORS BERNARD VAN ZYL. PH/L/PASTUDE/i W EL FIG. 6

ATTORNEYS Unite States This invention relates toan inertia actuated sensing and timing mechanism of the type which may itself be a source of operating energy. More particular-ly, the invention relates to an energy storing device which may at once provide the ydual functions of sensing la degree of accelenation or deceleration and also effecting the operation of various mechanical and electrical devices as, for example, for energizing Ia delayed spring switch mechamsm.

The accelerometer art has long used accelerometers as an acceleration measuring Iand/or trigger device wherein at a given degree of acceleration a switch or triggering mechanism may be actuated automatically. This has been accomplished mechanically, for example, in a missile, by rotating or unidirectionally driving the accelerometer mass so as to bring into coincidence levers which in turn may close trigger circuits. Electrical switching has also been bsed in combination with accelerometers las, for `example, when arranging a system so that when the accelerated mass has been driven la given amplitude corresponding to a predetermined amount of acceleration `or deceleration, responsive electronic means (eg. switch contacts closing) may trigger the detecting and actuating mechanism. Characteristically such vsystems have involved many components. Among them `would be the mass which is to be accelerated, the spring or restraining means against which the mass is to move in `a controlled fashion, channelling or retaining means to direct the movement of the mass either rectilinearly or unirotationally, switch or trigger means of the lmechanical or electrical type as seen above, and a source of power which the switch means is to release to act upon a lgiven signal or control device. As one `would expect, this combination of varied land necessarily precisely itting and exactly positioned parts must lbe arranged very carefully so that cooperation is intimate, of quick response, and accurate. This means that it takes the coordination of many moving latent parts as well as the weight of these many cooperating parts to make up `this small but intricate acceleration triggering system. With the multitude of yaccelerometer applications and environments today, it is essential, if not crucial, to minimize the weight of such a triggering assembly as well las to reduce the number of cooperating parts which must be intricately fitted. These components are diiiicult to make and, of course, are open to la multiplicity of possible sources of failure. In addition to this there is the necessary expense involved in producing and litting these many intricately assembled parts and assuring that they cooperate precisely. Consequently, any improvement in la system today which reduces the mass as well as the number of parts in a triggering device which is apt for precise yacceleration measurements in highly subtle and complex systems, ias, for example, a missile package, is of utmost importance for military applications, scientific research investigations and business or commercial; applications.

, Thus, it is seen that improvements in the area of simplifying a system and reducing weight yare vital ones in the aoce-lerometer art. These are two of the problems which the instant invention solves. As will appear below, the invention disclosed herein accomplishes simultaneously the dual `functions of sensing acceleration `and effecting operation of :a switchin-g mechanism which is to be triggered in response. It accomplishes these improvements in a manner which also serves to reduce the weight and the number `of parts in a system, thus simplifying and miniaturizing it.

The instant invention has been able to dispense with the` power source, a switch and la separate battery in an accelerorneter device thus reducing weight and the number of parts with the obvious attendant advantages, especially in a missile environment. The instant invention has taken what was heretofore an yaccelerometer measuring device and introduced the separate andV signiiicant function of acting as itsown energizer for the trigger means to be actuated by the accelerometer.

yIt is, therefore, an object of this inventionto provide lan improved sensing and timingdevice whereby number of parts and weight are reduced in comparison to prior art devices so as to simplify and miniaturize the mechamsm.

It is a Ifurther object of this invention to provide a device which may also be utilized to` render effective trigger means operatively connected thereto.

A still further object of this invention is to provide a device which, `at a predetermined acceleration level may itself effect operation of a switch or other responsive means.

Another object of this invention is to provide a device wherein the massas it moves underacceleration provides a power source las well .as a sensing instrument.

Other objects and many of the attendant advantages of this invention will be readily appreciated as it becomes better understood by reference to the following detailed description when'considered in connection with the accompanying drawings wherein:

. FIG. l lis a diagrammatic elevational view of a device constructed in accordance with the present invention;

FIG. 2 is an elevation view of the apparatus for starting Kand locking the Junghans escapernent mechanism of FIG. 1;

lFIG. 3 is a sectional view of an alternate arrangement of FIGA, wherein the restraining means itself serves as an operating means;

FIG. 4 is a view similar to FIG. 3 illustrating another arrangement of the device wherein a second restraining spring is employed;

FIG. 5 is la view in perspective of an `accelerable mass package wherein other components are used 'for purposes of constituting the mass.

FIG. 6 is a top View of another accelerahle mass package including the spring wherein .the spring is wound by moving its ratchet along the teeth of the track. n

This device is a gravity actuated sensing and timing mechanism that senses a predetermined value of acceleration or conversely deceleration and performs various mechanical and electrical functions at specific intervals after sensing occurs. The device also has the ability to return to a zero or steady-state condtiion Vif external forces should cease to act upon it. Y

Referring now to the drawings, there is shown in FIG. 1

thereof a sensing and timing device comprising a mass 61 balanced upon a spring system 62- in such a manner that when the mass moves to a desired position under the influence of an external force that is traveling in the downward sense, a fixed rack 64 aixed to mass 61 winds the main spring in the clock system 63 which is mounted externally of 61 and which consists of a barrel, mainspring and Junghans escapement. In the rest position, the spring is not wound and when the mass moves downward its rack attached thereto Winds the clock mechanism. When the mass lcomes in its downmost position, the Junghans escapement is released. After a delay determined by the Junghans escapement, functions such `as switch actuations :and trigger releases may be accomplished. The Junghans escapement is not actuated until the mass reaches the desired position, `at which time it is released and the clock runs performing any number of initiating or 'triggering functions such as closing 'switches and energizing control systems. lt should be noted in this gure and throughout the specification that the mass 61 may comprise any convenient -group-ing of many of the components used for differ-ent other functions such `asl shown in FIG. 5 wherein the mass consisting of tray with its winding rack attached and situated on which are a battery (B) and switch assembly (SW). FIG. 6 shows a different form 'of this same general idea.

In FIG. 2 is shown the Junghans escapement starting 'and Vlocking device used in connection with the clock mechanism-of FIG. l, to control the operation of the Laforesaid escapement. This system, which provides the starting andi-locking of the Junghans escapernent, is a method for restraining lan escapement lever in a springloaded condition so that when it is released the escapement which is inherently a non-self-starting escapement, will be started running. The system also provides a method of recycling, that is, it will move the escapement lever to the locked position without damage to any of the escapement cor'n-ponents.V The system is initiated by rotating a half shaft 5 enough to allow the release lever 4 to rotate counter clockwise. The indexing spring bears upon the indexing `pin 9, `is attached to indexing wheel 3 and drives the indexing Wheel and its shaft until the indexing pin and indexing spring reach a dead-center condition. The rotations of the indexing wheel cause the escapement lock 2 to move beyond the orbit of the escapement lever 1, thus allowing the escapement to run. Recycling is accomplished by driving .the recycling wheel 7 by a re-Wind motor (not shown). As the recycle Wheel rotates the engaging pin 6 comes Vinto contact with the release lever 4 and causes yit to -rotate labout its axes until the indexing pin arrives at a point in its orbit which allows the indexing spring toltake over and drive the release lever 4 until the latter comes to rest against the starting half-shaft 5. The system is once again ready for a new cycle of operation. Provision must be made to stop the rewind motor after the indexing spring begins to drive the indexing Wheel and also provision must be made tov return the half shaft to a locked position prior to the completion of the rewind cycle.

In FIG. 3 there is shown an arrangement whereby the spring restraining the mass is itself serving as an energizing source. In this arrangement mass `21 which traverses the channel between slides 25 and 25 and has attached to it a winding -rack 24 which in turn Iwinds Wheel 28 mounted on a shaft Z3 on which is in turn mounted a spring Z2 to be wound by the movement of this rack 214. Thus,

when the mass 21 moves under acceleration or deceleration down the channel and pushes the rack which winds the spring and its shaft by means of a 4wheel 26 mounted thereon. This arrangement is illustrative of how the vided by conventional escapement Ztl; shown attached to device can both sense the amounts of acceleration and charge an energy-storer (eg. spring) to be used in a system actuated by the accelerometer -at a predetermined degree of acceleration.

In FIG. 4 is shown schematically a system exactly analogous to that of FIG. 3 except that the restraining spring in this instance is a separate, oppositely-mounted spring 29. This figure illustrates simply the concept of using an Aaccelerable mass [to iWind `the actua-ting spring in a diiferent embodiment. v

In FIG. 5 is shownv the concept of using additional components together `with Ian accelerable tray to constitute the mass. t Intthis 'arrangement there is la signicant saving in Weight due to -t-he fact that instead of a non-functional mass acting las the measured mass in the accelerometer, the

mass of the otherwise functional components is itself the measured mass. This, of course, eliminates this lnonJfunctional mass and is also an invaluable saving in weight and space. This is la vital feature in la missile package. In the embodiment :shown in this ligure the mass comprising a tray T on which is situ-ated a batteryV mechanism B and a `switch package SW. With the advent of miniaturized battery and switch components, the form the components may take has become suitable for mounting on a holding tray as in an lillustration and allow them to serve as the accelerable mass. c

In FIG. 6 there is shown an |arrangement for using the spring means, With its dual energizing andV restraining functions, as a par-t of the sensing mass. In this embodiment there is shown a tray T on which is mounted acomponent such as switch SW, battery B, and, especially, the spring fand clock mechanismwhich is to serve both as the restrainin-g l'means for the accelerated mass and as the energizing means for Ithe clock mechanism. As will be apparent from'ithe drawing, when the mass package on the tray moves under acceleration the toothed sidewall S2 of the chute, along which the mass is 4to move, `will turn the 'wheel W intermeshing with the teeth thereon so -as to wind the spring in the spring package SP. In this embodiment not onlylhave a separate restraining spring and non-functional'mass been dispensed with, but the combination energizing and restraining spring itself serves as a functional part of the sensing mass. The extreme simplicity 'and miniaturization of :this combination will be apparent to one skilled in the missile packaging art where even a slight -saving in space, weight or number of parts is a` major objective.

- FIG. l also illustrates -how -theres/training spring serves also Vas an energizing spring for 'the clock mechanism. It is to be understood, of course, that the foregoing disclosure relates .only -to the preferred embodiments of the invention Iand that various modifications and 'alterations may be made therein without departing yfrom the spiri-t Iand scope ofthe invention. From the above, Vitshould be obvious that the invention offers-a new and improved accelerometer mechanism 'wherein the inventive features comprise: using the restraining spring ofthe ac-celerome-ter to serve the dual function of restraining the mas-s and energizing la clock mechanism, making `the weight comprising the accelerorneter mass functional, in dispensing with all non-functional Weight and also in using the movable mass itself to create energy which may be transmitted to a clock sensing or control mechanism.

Theprinciples of the instant invention have Wide application in the design of instruments using a moving body las one of the' measuring elements. Of course, an obvious application of lsuch a principle i-s that fof the embodiments disclosed and illustrated, namely, inertia actuated devices fused to sense acceleration and deceleration. Such devices have Wide and useful application in a missile control complex instrumentation.

Obviously many modilications and variations of the invention are possible in light of the above teaching. It is, therefore, to be understood that the source of this invention is to be considered as limited only by the scope and limitations `of .the appended claims.

What is claimed is:

1. In a force sensing and timing apparatus,

a base,

a pair of supports carried by said base,

`a mass slidably mounted on each of said supports,

a spring carried by each support of said pair of supports in engagement with said mass and the base for yieldably maintaining the mass in an initial suspended position,

a rst toothed member mounted on the base,

`a second toothed member movably mounted on the mass and cooperating with said iirst toothed member,

a clock mechanism mounted on the mass and windable lby movement of the second toothed member during movement of the mass from said initial position in response to the force sensed thereby,

said clock mechanism including an escapement device,

and

means operatively connected to s'aid escapement device lfor selectively starting 'and stopping the escapement device.

2. The `apparatus according to claim l, wherein the means 'for starting and stopping the escapement device includes means -to block movement of the escapement device,

rotatable means upon [which said blocking means is pivotally mounted,

means to rotate said rotatable means, and

means to `selectively prevent rotation of the rotatable t3 member for yieldably supporting the mass in a suspended position,

la rack mounted on the base member,

a pinion rotatably mounted on the mass and cooperating with said rack,

a clock mechanism including an escapement mounted on the mass and Windable by said pinion as the pinion moves along the rack during movement of the mass in response to a sudden shock received thereby, and

means for starting and locking said escapement,

said last named means including blocking means to block movement of the escapement,

rotatable means rupon Iwhich said blocking means is pivotally mounted,

means to rotate said rotatable means, and

means to selectively prevent rotation of the rotatable means.

4. The apparatus according to claim 3 `wherein said means for starting and locking the escapement includes:

a locking lever to block movement of the escapement,

1a rotatable indexing Wheel having a pin upon -Which said locking lever is pivotally mounted,

a release lever rigidly mounted on said indexing Wheel,

resilient means in engagement with the pin and urging the indexing wheel and release lever in one direction, and

means to selectively block movement of the release lever in said one direction, so that when the release lever is not blocked said resilient means Will rotate the indexing Wheel andthe release lever in a manner to remove the locking lever from blocking relation with respect to the escapement.

References Cited in the file of this patent UNITED STATES PATENTS 2,486,362 `onrten oet. 25, 1949 '2,s36,11s Hjeim May 27, 195s 2,928,347 Marsan Mar. 15, 1960 FOREIGN PATENTS 198,865 switzerland my 15, 193s 

1. IN A FORCE SENSING AND TIMING APPARATUS, A BASE, A PAIR OF SUPPORTS CARRIED BY SAID BASE, A MASS SLIDABLY MOUNTED ON EACH OF SAID SUPPORTS, A SPRING CARRIED BY EACH SUPPORT OF SAID PAIR OF SUPPORTS IN ENGAGEMENT WITH SAID MASS AND THE BASE FOR YIELDABLY MAINTAINING THE MASS IN AN INITIAL SUSPENDED POSITION, A FIRST TOOTHED MEMBER MOUNTED ON THE BASE, A SECOND TOOTHED MEMBER MOVABLY MOUNTED ON THE MASS AND COOPERATING WITH SAID FIRST TOOTHED MEMBER, A CLOCK MECHANISM MOUNTED ON THE MASS AND WINDABLE BY MOVEMENT OF THE SECOND TOOTHED MEMBER DURING MOVEMENT OF THE MASS FROM SAID INITIAL POSITION IN RESPONSE TO THE FORCE SENSED THEREBY, SAID CLOCK MECHANISM INCLUDING AN ESCAPEMENT DEVICE, AND MEANS OPERATIVELY CONNECTED TO SAID ESCAPEMENT DEVICE FOR SELECTIVELY STARTING AND STOPPING THE ESCAPEMENT DEVICE. 